The Saline County journal. [volume] (Salina, Kan.) 1871-1893, 1887-09-01
TOMATOES AND CYCLONES.
ne DIRsrsnos IN ths Formation % Tor
nado-WhIris aad yFhiririnds.

ne DIRsrencs IN the Formation ~ Tor
nado-WhIris sad Whiriuinds.
When the conditions Of atmospheric
instability have given birth to tor
made. the fact Is announced 10 the OBJ
server by a sudden gathering Of dark.
sWift-Whiriing clouds. from which de-
pend q wriihing. serPent-like body
formed Of condensed VapuE. This
writhing column extends rapidly
downward until it touches the ear h
When Il attains the surface 10 becomes
audible from the violent rending &c
tons which Il creates upOn that sur
face. As soon a. the whirl is created
Il begins 70 move aWay-generally
toward the nOFtheast-fOr the evident
reason that the upper cold layer If ali
against which Il originates has. in the
northern hemisphere. a movement in
thst direction. In its path over the
surface the eireling movement Of the
Writhing air ana the sucking action Of
the partial vacuum in the central por-
ton Of the shaft combine % bring
about an extreme devastation. On
the outside Of the Whirl the air, which
rushes in n circling path toward the
vortex. OveTturns all movable objects.
and in the center these objects. il not
too heavy. are sucked mp as by great
air-pumP Thus the roofs Of
hOuses-bOdies Of men and animals
may be lifted to great elevations until
they are tossed by the tumultuous move
ments beyond the limits Of the ascend
ing currents and fall upon the earth
Where the center of the whirlWind
passes over a building the sudden de-
crease in the pressure 81 the outer air
often causes the atmosphere which is
contained within the walls suddenly
TO press against the sides Of the struct-
ure. 50 that these sides are quickly
driven outward as il by a charge II
gunpowder. Il is not unlikely that
the dimunition Of pressure brought
about by the passage Il the interior II
the whirl over building may b. about
as much us is indicated by the fall Of
four inches in the barometer. This is
equivalent TO a change in the pressure
amounting to about three hundred
pounds 10 the square foot This force
operates 10 burst out the walls II a
building. Il is not improbable that
the diminutiOn Of pressure may b.
much greater than this. but even the
amount named Is sufficient 10 account
for the bursting out of the friil-walied
structures which these deyasj ating
movements encounter in the western
parts Of the United States.
The way in which these tornado
whirls are formed differs in certain es-
sential particulars from the way in
which WhIrlwinds are created. AS has
been well shown by Prof Fcrrel. The
most important points of difference are
a follows: The dust-whirls are due Ia
the heating Of a thin layer Of air next
the ground. The small mass Of this
layer prevents its upward whirling
from bringing about any powerful
movements Of the atmosphere. In the
tornado the heat Of the lower air has
different origin. When a cyclone
passes over the surface Of the country.
certain peculiar movements Of the al
musphere which il produces bring
large volumes Of the warm aud moist
ened air TO the earth's surface and
oyerlay them by a cool stratum. This
layer Of warm, moist air tends TO rise
NJ for the same reason that the thin
layer Of dry air which forms the dust
whirl is impelcd upward. but on &C
count Of its great mass the intensity Of
the upward urgence is far greater. IL
the sand-whirl the upward motion be-
gins close TO the earih's surface. for
the reason that the stratum which Is
impeled upward is very thin. but in
the tornado the stratum Of heated
air is usually about a thousand
feet thick; therefore its Whirling
action naturally originates At the up
per surface Of the hot layer. for it is al
that point the upward motion begins.
Starting in this upper region. the whir
extends progressively downward. just
ms in the bath-tub the whirl extends
progressively upward from the point
at which the motion originated. until
the wind may touch the surface Of the
earth. When these whirls begin they
only involve n small part Of The air
about the point of origin. and 80 the
acquired vel"city Of the particles when
they come TO the center il not great;
but gradually they suck air from far
Their aud farther away. A. the field of
supply becomes larger. aud the par
ticles move from a greater distance,
they approach hat center with greater
speed, and the spiral widens and turns
with accelerated velocity.
fortunately the paths Of toruadnes
are ordinarily very narrow-the Wild
est have a diameter Of less than two
miles; the narrOwest Of only forty feet.
In most cases a tornado is seriously
destructive over a width not exceed
ing five hundred feet The length
Il the tornado's path across
the country does not commonly exceed
thirty miles. and il generally traverses
the distance in about an hour. When
the upward corkscrew motion Of the
outer part Of the spiral aud the swifter
upruSh Of the air through the central
shaft have drained away the most Of
the warm air which gave birth to tho
motion. the tornado dies away The
equilibrium Of the air-masses is for
time restored. the heavier air has fall
len down upon the surface. aud the
warm air. spreading literally As il al
iains the level Ia which Il tends. comes
into a state Of quiet Assuming "a
width Of the destruction brought about
by the storm at six hundred feet, and
the length Of its journey at thirty
miles. we find that the area Of its de
VISITATION amounts 10 about two thou
sand acres. or 10 square area about
two miles on side. Over this area IN
destruction is ordinarily more COM
plete than that which occurs IN tin
most severe earthquakes ~ 8.
Shaier. ia ScylbHer's Aaga.ine
HOW COMETS ARE FOUND.
Interesting Information Impaired BY As
truuorn-r Iiarnzrd.
Prof F. f. Barnard, the astronomer
Of the Vanderbilt University. was asked
the other day how comets are found.
Besides a knowledge Of astronomy